Devices for elevating a liquid from a liquid bath



Fgbo 25,1958 L.- BIRKIGT 2,824,521

' DEVICES FOR ELEVATING A LIQUID FROM A LIQUID BATH Filed Sept. 9, 1954 2 N VE N TD R 400/5 E/IPK/GC ATTDHNEY Unite States PatetitO DEVICES FOR ELEVATING A LIQUID FROM A LIQUID BATH Louis Birkigt, Pregny-Geneva, Switzerland, assignor to Brevets Aero-Mecaniques S. A., Geneva, Switzerland, a society of Switzerland Application September 9, 1954, Serial No. 455,022

Claims priority, application Luxemburg September 22, 1953 2 Claims. (Cl. 103-101) The present invention relates to devices for elevating a liquid and it is more especially although not exclusively concerned with devices of this kind for creating an upward circulation of lubricant through an apparatus or mechanism the parts of which to be lubricated are located above the level of an oil bath, which is the case in particular of some spinning or twisting spindles and in particular of those driven through a worm and a worm wheel.

The chief object of my invention is to provide a device of this kind which is better adapted to meet the requirements of practice than those known up to this time and in particular which is simpler and of a safer operation. It is known to constitute such devices by a hollow rotating shaft extending substantially in the vertical direction and the lower end of which is immersed in the liquid to be elevated, said lower end being surrounded at a small distance therefrom by a cup-shaped member the bottom of which is provided with a hole located opposite the lower end of the passage existing in the hollow shaft for the inflow of liquid thereinto, the area of said hole being smaller than the cross section of said passage existing at the lower end of the tube. Now, according to my invention, the lower portion of the device is arranged in such manner that the liquid reaches the hole provided in the bottom of the cup-shaped member through a passage, and preferably an annular one, limited in the outward and upward direction by a frusto-conical wall the smaller basis of which is constituted by the edges of said hole, whereby the liquid already has a substantial upward velocity when it enters said hole.

Other features of my invention will become apparent in the course of the following detailed descripti n of some specific embodiments thereof with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 is a diagrammatical view showing in axial section spinning spindle driven by means of a worm and a wormv gear and provided with a lubricant device according to my invention.

It is desired according to the present invention to elevate a lubricant, for instance oil, from an oil bath H into a mechanism located above said oil bath.

, It is already known to make such a device in the following fashion.

The mechanism to be lubricated includes a hollow shaft or tube 1 rotated by this mechanism and which may constitute one of the elements thereof, said shaft extending in a substantially vertical direction, and the lower end thereof being immersed in oil bath H.

The lower end of this hollow shaft 1 is surrounded, at a small distance thereof equal to j, by a fixed cup-shaped member 2 (advantageously carried by the casing of the mechanism) the bottom of which is provided with a hole located opposite the lower end of the passage P existing in shaft 1 for the passage of the liquid, the area of said orifice 0 being smaller than the cross section of passage P at the lower end thereof.

Furthermore the side wall of cup-shaped member 2 is located above the level of the surface of the oil bath H, whereby lubricant can reach passage P only through the hole 0 provided in the bottom of said cup-shaped member.

With such a lubricating device, the oil that has entered cup-shaped member 2 is given a centrifugal movement by the hollow rotating shaft 1 and is therefore applied against the side wall of said cup-shaped member. As the clearance j between said side wall and the hollow shaft is very small, the oil thus projected outwardly cannot escape to any substantial degree through the space hetween the hollow shaft and the cup-shaped member which surrounds it. The pressure increase which results from this causes an upward movement of oil along the inner wall of passage P.

It should be remembered that in the known constructions of this type based upon the principle above set forth, the bottom of the cup-shaped member 2 was fiat which causes the liquid to undergo a sudden change in the direction of its travel when passing through hole 0. As a matter of fact, this liquid first travels in the centripetal direction along the outer face of the flat bottom of said cup-shaped member, after which it moves outwardly 'to reach the inner wall of passage P. In these conditions, the upward component of the velocity of the liquid passing through hole 0 is very small and the upward velocity of the liquid starts increasing only after it has penetrated inside the cup-shaped member.

The object of my invention is to increase the upward velocity 'of the liquid passing through orifice 0 and thus to increase the flow rate of the liquid passing through said orifice toward the parts to be lubricated.

According to my invention, the lower portion of the device and in particular the bottom of cup-shaped member 2 are arranged in such manner that the liquid reaches hole 0 through a passage p, preferably annular, limited in the outward end direction by a frusto-conical wall T, the smaller basis of the frusto-conical surface being constituted by the edge of hole 0.

Thus, the liquid which is moving toward orifice o by flowing along frusto-conical wall T is given an absolute velocity having a substantial vertical component when said liquid reaches the edge of said orifice. At this time, the liquid already has a substantial upward velocity which corresponds to said vertical component and the flow rate of the liquid through hole 0 is consequently increased.

Advantageously, this frustO-conical wall T is constituted by the bottom of cup-shaped member 2 itself and the bottom portion of said cup-shaped member is of a shape analogous to a bottle bottom.

Concerning passage p it may advantageously be given a frusto-conical shape limited outwardly by wall T and inwardly by the outer wall of a frusto-conical piece 3 disposed opposite orifice 0. i I

Advantageously the bottom portion of passage P is given a shape corresponding to that of the bottom of cupshaped member 2.- In other words, the inner edge of the bottom portion of hollow shaft 1 is of frusto-conical shape. The eddies which are created by the centrifugal force then develop in a space A which has substantially the shape of a frusto-conical space of a direction similar to that of frusto-conical passage 2. Experience has taught that this was advantageous in order to develop at the bottom of shaft 1 a pressure which causes the liquid to rise along the inner wall of the passage P provided in said shaft 1.

Patented eb. 25, 1958' I will now describe the application of such a lubricating device to a spinning spindle driven by means of a worm wheel 4 and a worm 5, such an apparatus including a rotating vertical hollow shaft or tube 1 acting ,as support for worm 5.

Such an arrangement is illustrated by Fig. 2.

The mechanism includes a bobbin-carrying spindle member 6 resting at its lower end in a movable step-bearing 7. The spindle member extends with some play inside tube 1 and it is coupled with said sleeve through means (not shown) which enable said spindle member to have a limited angular displacement.

This bearing 7 includes a flange 7b resting on the bottom of an annular socket 19 fixed at the top thereof in a sleeve 14 rigid with a supporting arm 9a integral with the casing 9 of the machine.

Lateral movements of step-bearing 7 are limited by a sleeve 8 coaxially surrounding said bearing 7 with a very slight annular play.

The lower end of sleeve 8, of frusto-conical shape, is resting on a bearing 14a of corresponding shape of sleeve 14.

Another coaxial sleeve 16 is freely mounted between sleeves 8 and 14.

In the casing 9 of the apparatus there is provided an oil bath H the level of which is above the lower end of rotating tube 1.

The immersed portion of said tube 1 is surrounded by a fixed cup-shaped member 2. The top flange of said member 2, and also the top flange of socket 19, are caught between a shoulder provided in fixed sleeve 14 and the external cage of the lower ball bearing 10 which guides said sleeve, with the interposition of a ring 11.

The bottom of said cup-shaped member 2 is provided with a circular hole 0 having a diameter smaller than the inner diameter of tube 1 but greater than the diameter of spindle member 6 at the point thereof which passes through said hole. Thus there is provided, between the edge of hole 0 and the spindle member, an annular passage for the inflow of oil which is to move upwardly between the walls of spindle member 6 and tube 1 in the form of a film (the thickness of which decreases upwardly) formed along the inner wall of said tube 1.

The flange 7a of step bearing 7 does not extend continuously around said step bearing but is provided with radial notches, as visible on Fig. 2 on the left hand side of spindle 6. Similarly, the bottom of socket 19 is provided with corresponding notches. Thus, oil from the bottom of easing 9 can circulate freely, up the annular r I will now give, by way of example, some information concerning the relative dimensions of some of the elements which consitute this lubricating device (shown by Fig. 2 at a scale corresponding to twice the true dimensions of the parts).

Excellent results were obtained in the case of a spindle including a rotating tube 1 having an internal diameter averaging 1 cm. Through this sleeve extends a spindle member 6 having near the lower end of tube 1 a diameter averaging 0.5 cm. Passage p and space A had a thickness averaging 0.5 mm. The clearance between the corresponding walls of tube 1 and cup-shaped member 2 ranged from 0.05 to 0.15 mm.

With such dimensions, the upward flow of oil between tube 1 and fixed cup-shaped member 2 are practically negligible but I may, by way of precaution, provide in tube 1, at the level of the upper part of fixed cup-shaped member 2, an annular recess C in which the amount of oil that may have been elevated can accumulate.

Furthermore, in order to prevent in all cases the oil driven into space C from reaching lower bearing 10, I advantageously provide this bearing at a higher level with respect to the upper edge of cup-shaped member 2, which is obtained by inserting a spacing ring 11 between the outer cage of said bearing and a shoulder rigid with cas- 9, such a ring serving advantageously to fix the cupshaped member 2 in position. I provide in the flange carried by the upper end of said cup-shaped member oil return holes 12 so that any amount of oil which may have passed between tube 1 and the cup-shaped member 2 is returned to the oil bath H without having reached bearing it it should be noted that, in the embodiment of my in vention which has just been described, the lubricating device will be still more eificient than that illustrated by Fig. l, due to the fact that the oil about to enter cupshaped member 2 is centrifugated not only by rotating tube 1 but also by the portion of the spindle member 6 which extends through the bottom of said cup-shaped member.

The upward circulation of oil thus obtained can be used in particular for the following purposes: for lubricating the zone where worm wheel 4 is tangent to worm 5, a radial passage 13 being provided for this purpose in the wall of tube 1; and/or for lubricating an upper bearing (not shown) holding spindle member 6.

The lubricating device according to my invention has many advantages, and in particular it is highly eflicient. It is very simple whereby any causes of breakdown are eliminated. Furthermore it is capable of Working cor rectly whatever be the speed of revolution of the spindle.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efiicient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

1. In a structure for lubricating a spinning spindle mechanism including a spindle and a worm and worm wheel gear for driving said spindle, which structure comprises, in combination, a casing the bottom of which forms a chamber containing an oil bath, a tube coaxial with the worm and rigid therewith, the lower end of said tube being immersed in said oil bath, said tube coaxially surrounding said spindle with an annular space therebetween, a cylindrical cup-shaped member 2 fixed with respect to said casing and surrounding the lower end of said tube at a small distance therefrom, the cylindrical wall of said cup-shaped member adapted to extend to a level above that of said bath, said cup-shaped member having a bottom, the bottom having a hole concentric with said spindle for the passage thereof, said hole being of a diameter smaller than the inner diameter of said lower end of said tube, the bottom of said cup-shaped member having upper and under faces, the under face being of frusto-conical shape so that the axial sections thereof diverge in the downward direction, and a step bearing for the lower end of said spindle, said hearing being fixed with respect to said casing, the upper face of said bearing being located close to the under side of the bottom of said cup-shaped member and being of frustoconical shape so that the axial sections thereof are at least substantially parallel to those of said member bottom under face, said under face of the cup-shaped member and the upper face of said bearing cooperating to form a passageway for the oil, the passageway being inwardly and upwardly directed whereby oil in the passageway is substantially free of a radial thrust due to centrifugal force by rotation of the lower end of the spindle.

v 2. A device according to claim 1 in which the upper face of the bottom of said cup-shaped member is close to the lower edge of said tube, said upper face and said lower edge being both in the form of frusto-conical surfaces at least substantially parallel to the frusto-conical surface of the under face of said cup-shaped member bottom.

References Cited in the file of this patent UNITED STATES PATENTS Anderson Jan. 10, 1939 Curtis Dec. 22, 1942 Birkigt June 8, 1954 FOREIGN PATENTS France Oct. 30, 1950 

